Disparities in Influenza Vaccination Coverage Rates by Target Group in Five European Countries: Trends over Seven Consecutive Seasons

Background: The primary objective of this study was to measure influenza vaccination coverage rates in the general population, including children, and in high-risk groups of five European countries during the season 2007/2008. An additional aim was to analyze coverage trends over seven consecutive seasons and to gain an understanding of the primary drivers and barriers to immunization.

Methods: Community-based telephone and mail surveys have been conducted in the UK, Germany, Italy, France, and Spain, yearly, since 2001/2002. Approximately 2,000 individuals per country and season were interviewed who were considered to be representative of the adult population aged 14 years and older. Data on the vaccination status of children were obtained by proxy interviews. The questionnaire used was essentially the same for all seven seasons. Five target groups were identified for the study: (1) persons aged > or = 65 years; (2) elderly suffering from a chronic illness; (3) patients suffering from a chronic illness; (4) persons working in the health care sector; (5) children.

Results: In the season 2007/2008, vaccination coverage rates in the general population remained stable in Germany. Compared to the coverage rates of the previous season, increases of 3.7%, 2.0%, and 1.8% were observed for the UK, Spain, and France, respectively, while a decrease of -1.5% was observed for Italy. Across all five countries, vaccination rates in the predefined target groups decreased to some extent (elderly) or increased slightly (chronically ill and health care workers). Vaccination rates among children varied strongly between countries and ranged from 6.1% in UK to 19.3% in Germany. The most powerful motivation for getting vaccinated in all countries was advice from a family doctor (58.6%) and the perception of influenza as a serious illness (51.9%). The major reasons why individuals did not become vaccinated were (1) the feeling of not being likely to catch influenza (39.5%) and (2) never having considered the option of being vaccinated (35.8%).

Conclusions: The change in general influenza vaccination coverage in the 2007/2008 season compared to the previous season was small, but decreases were seen in some target groups. The underlying motivations for and against vaccination did not substantially change. An effort to activate those driving forces that would encourage vaccination as well as dealing with barriers that tend to prevent it may help enhance coverage rates in Europe in the future.